1. 1.3 First Generation Computers 1.4 The Stored Program Computer Group 2

2. ABC The first electronic computer was built between 1939-1942 at Iowa St. University by John Atanasoff and Clifford Berry. This computer was called the Atanasoff-Berry Computer, or ABC. It used the binary number system of 1’s and 0’s which is used in computers still today. It contained hundreds of vacuum tubes used to amplify the power source given to the computer. Almost 50 years later, Atanasoff finally received full credit for the invention of the ABC.

3. The ENIAC In June 1943, John Mauchly and J. Presper Eckert began working on the ENIAC (Electronic Numerical Integration And Calculator) which was not finished until three years later in 1946. It was contracted to be used in WWII to calculate the trajectory of enemy artillery shells but because the computer wasn’t finished until 1946, the military was unable to use the ENIAC during the war. The ENIAC had solved a mathematical problem that would normally take a group of mathematicians 3 days to complete in 20 seconds on it’s first outing. The ENIAC weighed 30 tons and occupied 1500 sq. ft. (I.E. roughly a three bedroom house) It contained over 17,000 vacuum tubes which produced enough heat to where the room had to be cooled by special fans. http://www.youtube.com/watch?v=k4oGI_dNaPc

4. Universal Machine This concept was envisioned by Alan Turing in the late 30’s and 40’s to help reduce the amount of wire pulling need to switch the task of the computer. Instead of changing the wires, he envisioned changing the programs instead which would make things faster and easier.

5. CPU In 1945, John von Neumann presented his stored program concept. The “CPU” (Central Processing Unit) consisted of different elements used to control all the functions of the computer electronically without flipping switches or pulling wires to change instructions.

6. EDVAC & EDSAC Mauchly, Eckert, and von Neumann designed and built the EDVAC (Electronic Discrete Variable Automatic Computer) and the EDSAC (Electronic Delay Storage Automatic Computer) These computers were designed to solve many different problems by simply entering new instructions that were stored on paper tape. Those instructions were in Machine Language which consists of 0’s and 1’s. Those numbers represented a switch, 0’s for off and 1’s for on.

7. UNIVAC The Third computer to employ the stoned program concept was the UNIVAC (UNIVersal Automatic Computer) which was built by Mauchly and Eckert. In 1951, the first UNIVAC was sold to the U.S Census Bureau. Only large corporations and the government could afford to buy the UNIVAC because the product used so many vacuum tubes. This computer had the ability to perform up to 1,000 calculations per second which made them poipular despite the price.